   (->> (process-deps-cljs cp source-path root-contents)
        (inspect-resources cp)))
 
+;; if a jar contains a cljs.core file (compiled or source) filter out all other files
+;; from that directory as it is compiled output that shouldn't be in the jar in the first place
+(defn quarantine-bad-jar-contents [^File jar-file resources]
+  (let [bad
+        (->> resources
+             (filter (fn [{:keys [resource-name] :as rc}]
+                       (or (str/ends-with? resource-name "/cljs/core.js")
+                           (str/ends-with? resource-name "/cljs/core.cljs"))))
+             (first))]
+
+    (if-not bad
+      resources
+      ;; .jar file contains a compiled version of cljs.core
+      ;; filter out all sources in that directory, likely contains many other compiled
+      ;; and uncompiled sources
+      (let [{:keys [resource-name]} bad
+            bad-prefix (subs resource-name 0 (str/index-of resource-name "cljs/core."))
+
+            filtered
+            (->> resources
+                 (remove (fn [{:keys [resource-name] :as rc}]
+                           (str/starts-with? resource-name bad-prefix)))
+                 (vec))]
+
+        (log/warn ::bad-jar-contents
+          {:jar-file (.getAbsolutePath jar-file)
+           :bad-prefix bad-prefix
+           :bad-count (- (count resources) (count filtered))})
+
+        filtered))))
+
 (defn find-jar-resources
   [{:keys [manifest-cache-dir] :as cp} ^File jar-file]
   (let [checksum

      (index-rc-remove index resource-name)
      )))

(defn start [cache-root]
  (let [co
        (doto (CompilerOptions.)

           ;; closure library test files
           #"^goog/demos/"
           #"^goog/(.+)_test\.js$"
           #"goog/transpile\.js"
           ;; closure compiler support and test files
           #"^com/google/javascript"
           #"^jdk/nashorn/*"
           ;; just in case the :output-dir of a dev build is on the classpath
           #"cljs-runtime/"}

